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50W RMS speakers on a 100W RMS x 2 @ 4 Ω amp

3K views 10 replies 4 participants last post by  ShardAerithes 
#1 ·
Hey guys,

I just got a new (to me) Bugeye Wagon recently, and I am doing some basic mods to it.

I'm pretty strapped for cash at the moment, but a friend had a set of older Pioneer 6.5" 3-ways that say 200W max, 50W RMS.

I made some adapters so they'll clear the windows and I am in the process of installing them. I am also doing a little hushmat behind them and on the door itself. Making sure they are good and sealed up. Of course they won't have a dedicated airspace but I want them to sound their best, even though they're essentially junk.

I would like to baffle them but don't know what to use as a baffle.

I have a basic Kenwood deck which probably puts out something like 13-18W per channel real power.

I also have a really nice amp sitting around that would put out 100W RMS per channel when run at 14.4V. I know it'll be less than that if I put it in my car, but I am still uneasy about running that much power through these old Pioneers.

I know I can use the gain to keep them within a reasonable power level, but I'm not sure that is proper use of the gain. So I would probably try to properly tune that, and be disciplined about the volume knob. Still, I am concerned I am going to blow these up and have nothing until I can buy a nicer set of like HAT or JL audios.

So what do y'all think? 13W RMS off the head unit into these paperweights, or go for it and put 100 W per channel into them? I plan to eventually put a sub into the car and I'm sure it'll overpower the speakers if they're not amped too. I am more about sound-quality than volume, though.

Thanks for your time! Hopefully soon my cash flow will grow and I will be able to get some real speakers in there :)
 
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#2 ·
Does the amp have a high-pass filter? If so, I'd use it to block the deepest bass notes. That should help the speaker's longevity. Find out where the head unit's signal starts distorting (max clear volume). Find out where the speakers start distorting. Turn up the head unit to the max undistorted volume and adjust the gain so that it's just below where the speakers start distorting. Should give you max volume and the speakers should be fine. With most speakers, you'll know if you're putting too much power to them.
 
#3 ·
If the speakers are not overdriven, underdamped, or clipped, and if you implement relatively steep filters, I can't imagine there'd be an issue.

On the one hand it is unlikely IMO that the speakers will hold up for any length of time to 50W RMS despite (or maybe, because of...) what they state, but on the other it is just as unlikely in my view that the amp can output 100W RMS for any length of time.

For what it's worth I've used 200+W RMS (actual) amps (pro grade and domestic, not mobile) to drive 50W RMS speakers that were very costly and there were no dramas. Self restraint is the way to go.

If you do blow them up you can scavenge for replacements for ~$30 or so; try used or PE for example.
 
#4 · (Edited)
Hi, thank you guys for the replies.

Yes the amp has a high pass filter that I would use. The amp is a rockford power series and it's rated at 100W RMS for 2 ohm or 4 ohm, so I imagine it is pretty strong. Self restraint/keeping the speakers out of distortion is something I think I can manage.

It sounds like I should give it a shot anyway. I guess you're right that replacements would not be that expensive. I would be wanting $200+ speakers though, and I know I can't afford them right now :)

Now when you say underdamped, what do you mean? They don't have baffles or anything behind them except the door. The front and back waves are separated by wood adapters/the door/hushmat, and behind the speaker has some hushmat on the door skin, and the door has the air-barrier plastic intact, but they definitely don't have any kind of air spring, they're just free air. The surrounds are intact but they're not even rubber or anything, just treated cloth. I am definitely open to baffle/dampening suggestions.

btw SD_GR I like that quote from Sisko in your sig!
 
#5 ·
Self restraint/keeping the speakers out of distortion is something I think I can manage.
OK.

Now when you say underdamped, what do you mean? They don't have baffles or anything behind them except the door. The front and back waves are separated by wood adapters/the door/hushmat, and behind the speaker has some hushmat on the door skin, and the door has the air-barrier plastic intact, but they definitely don't have any kind of air spring, they're just free air. The surrounds are intact but they're not even rubber or anything, just treated cloth. I am definitely open to baffle/dampening suggestions.
Dampening in car audio is usually approached with a "kill the rattles" attitude but it should be used just like in any other application, to kill standing waves and and reduce resonances at antinodes. It would be determined by the T/S parameters of the speaker plus the design of the enclosure -- or in your case, if the speakers are intended to operate essentially without an actual enclosure. In any case, you don't want to reach a point where the compliance and mass changes (behind the driver, in the "enclosure" I suppose) let you reach Xmax for any given frequency at any given input level.

I think you can throw all that out the window and simply avoid overdriving the speakers now that I'm considering how needlessly complex it can become.

btw SD_GR I like that quote from Sisko in your sig!
The most damning thing of all is that I think I can live with it, and would probably do it again.
 
#9 ·
I've been running a pair of Infinity Reference 6.5" coax speakers in my front doors for years (I think I paid $40 for them). They're rated for 60watts RMS and I run them off of an Alpine PDX-4.100 amp which came with a test sheet showing a real output of 141watts RMS per channel (using high quality 14 gauge speaker wire). I have played the crap out of them, at VERY high volumes for extended periods of time (trying to blow them up). The funny thing is, with that much power going to them, the louder I turn it up, the better it sounds. I'm amazed they still work.. but it goes to show that in general, the more power the better.
 
#11 ·
Haha that is awesome! Inspiring for me to go out and get this amp installed! Nothing like good clean power, right? I had a pair of amped Infinity Reference Coax's in my STi. They sounded decent but the amp was garbage that I got for free (Audiopipe.) I've gotta stop using free equipment... lol

I don't think that's lazy. I think that's a terrific way to go. I've heard the difference active xovers can make. Comparing a good pro monitor in its passive vs. active form, the active will win in clarity and dynamics. Plus an active xover will give you slope options that you won't get easily with a passive setup. It may actually be the way to go (careful you don't spend more on the system than the car though...).
That is my issue, I always end up wanting to put way too much $$ and time into a car that isn't quite worth it... perhaps I'll do this when I can get into a newer body style STi like I dream about... *(first I need to grow my small business into one that isn't quite so small)*

I only paid $2700 cash money for this bugeye wagon. I own it outright which is cool. However it's a little rough around the edges, doesn't have premium package, little rusty... etc... runs good though, thankfully! It was completely stock when I found it. 270k miles and zero mods. Like, zero. Didn't even come with the factory boost gauge. It has the OEM alarm though, lol.

Honestly I'll probably find some cheap components with a passive xover on craigslist or ebay like JL C2s, or try out a pair of HATs. All depends on the budget and where it goes. I like to trip over dollars to save pennies, it's how I've always been. If I was smart I'd stop custom fabbing speaker adapter rings and contemplating my placement of hushmat and just fork out another $50 for rings and more hushmat. I could have spent all that time growing my business, which would improve my life/budget in so many ways...

Alas, I always want to improve what I have. This is the same mentality that has gotten me $15k+ deep into putting twin turbos on an NA 3000GT (myself and a friend did ALL the labor), then selling it after realizing how much of a waste of time/money it was... and regretting it... the same mentality that made me want to mod my 89 Camry V6 (first car)... thank god I never followed THAT dream...

In any case, it's been a fun ride and a good education... but nowadays I just want to drive a reliable, 500AWHP, tuned, quiet-until-you-floor-it, heated leather beast with a $5,000 sound system... anyone have $50k they want to lend me? :D

I guess I'll just stick with my free pioneer coaxials, my nice amp, a craigslist JL 12W6 that I hope to buy, a little hushmat, and stage 2. If I ever get to having another beast, this one will likely become my winter go-getter. Life sure can surprise if given the chance. :)
 
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